Figure 1: Illustration of the histological analysis processing stages in an ovine carotid artery. (b) Characteristic colors of the histological preparations, from left to right: elastin, smooth muscle, collagen, and the original image, where the three integrated constituents can be visualized throughout the arterial wall. (a) Similar discrimination with assigned fictional colors that allow a clearer visualization of the location of each wall constituent. Note the thick layer of smooth muscle in the tunica media and the disposition of collagen in the tunica adventitia.